Electro-mechanical actuator



1968 H. u. HJERMSTAD IETAL 3,3

ELECTED-MECHANI CAL ACTUATOR Filed Oct. 22, 1965 Jan. 23, 1968 H. u.HJERMSTAD ETAL ELECTRO MECHANI CAL ACTUATOR I an 1958 H. u. HJERMSTADETAL 3,364,752

ELECTRO-MECHANICAL ACTUATOR 4 Sheets-Sheet 5 Filed Oct. 22, 1965 gag h!!-l ull 1968 H. u. HJERMSTAD ETAL 3,364,752 I ELECTRO-MECHANICAL ACTUATOR 4 Q M w f z 2 w w h ,P w

,U 7 mW MW .v s. 7 H W W 2 H W W mfl my Z w United States Patent Ofilice3,364,752 ELECTRO-MECHANICAL ACTUATOR Hans U. Hjermstad, Chicago, andCarl J. Kopp, Arlington Heights, 11]., assignors to Electro-SealCorporation, Des Plaines, Ill., a corporation of Illinois Filed Oct. 22,1965, Ser. No. 501,049 13 Claims. (Cl. 74-2) ABSTRACT OF THE DISCLOSUREAn energy-storing and release mechanism, usable to actuate bomb shacklerelease devices and the like, which comprises a housing defining anelongated chamber, a plunger mounted within the chamber andlongitudinally movable therein from an energy storing cocked position toa released position, energy-storing means operable to move the plungerfrom the cocked to the released position, locking means engageable withthe plunger to releasably retain the plunger in the cocked position andfurther having an unlocked position disengaged from the plungerpermitting the energy-storing means to move the plunger toward thereleased position, and planetary cam means operably engageable with saidlocking means and moveable from a first position in engagement with saidlocking means to releaseably retain said locking means in said lockedposition and further movable to a second position permitting saidlocking means to move to said unlocked position.

This invention relates generally to an electro-mechanical energy storingand release mechanism, and more particularly relates to an improvedactuator mechanism of the type disclosed in United States Patent2,776,570 for controlling a bomb shackle release device.

General disclosure It is well known that the actuator mechanisms forcontrolling aircraft bomb release devices, as described and claimed inthe above-mentioned patent, must meet rigid design and operatingstandards before being adopted for use under adverse field conditions.Because of the necessarily limited supply of electrical power on mostmilitary aircraft, such bomb actuator mechanisms must be designed toimpart a substantial releasing force to the bomb shackle release leverswhen energized by a relatively small amount of electrical energy.Adverse field conditions further require the type of actuator mechanismsunder consideration to be very compact and light weight, easily andeconomically assembled and repaired, and capable of withstanding severetemperature, shock and vibration conditions.

The electro-mechanical actuator described and claimed in theaforementioned Patent 2,776,570 has been very successful in meeting theabove-mentioned structural and operational requirements for bomb releaseactuators. As illustrated in said patent, which is assigned to theassignee of the present application, the type of bomb release actuatorunder consideration comprises a spring-loaded plunger assembly which isreleasably locked in a cocked energy storing position by cam-operatedlocking and release means. In addition, the cam means which operates thelocking and release means is connected to a solenoid assembly or thelike which upon energization moves the cam and releases the locking andrelease means from the plunger, thereby permitting the spring toforcefully drive the plunger assembly against the release lever of anaircraft bomb shackle.

.This invention contemplates providing such bomb release actuators withan improved locking and release means and a novel planetary cam assemblywhich cooperate to releasably retain the plunger assembly in theaforementioned cocked energy storing position. It has been found thatthe addition to such actuators of the improvements in accordance withthis invention substantially enhances the structural and operationalcharacteristics of the actuator, and particularly decreases the amountof electrical energy needed to operate the mechanism. In addition, theimprovements in accordance with this invention substantially reduce thecosts of manufacturing the actuator by providing a mechanism which canbe readily machined with a minimum of critical tolerances and which canbe finally adjusted for maximum performance during assembly.

It is therefore an object of this invention to provide an improvedelectro-mechanical actuator mechanism suitable for use with an aircraftbomb shackle release device.

It is a further object of this invention to provide an improvedelectro-mechanical actuator which may be readily energized by a smallamount of electrical energy to impart a substantial releasing force toan aircraft bomb shackle release lever.

It is a still further object of this invention to provide an improvedactuator mechanism that is compact and lightweight, and which canwithstand severe temperature, shock, and vibration conditions.

Disclosure of a specific embodiment Another object of this invention isto provide an improved electro-mechanical actuator mechanism which maybe economically manufactured with a minimum of critical machinetolerances, and which may be accurately adjusted for maximum performanceat the time of assembly.

More specific objects and features of this invention will becomeapparent from a description of an embodiment thereof, as illustrated inthe accompanying drawings. In these drawings:

FIGURE 1 is an end view of the assembled actuator mechanism inaccordance with this invention;

FIGURE 2 is an enlarged cross-sectional view of the actuator taken alongthe line 22 in FIGURE 1 showing the actuator in the cockedenergy-storing position;

FIGURE 3 is a cross-sectional view taken along the line 33 in FIGURE 2;

FIGURE 4 is a fragmentary cross-sectional view taken along the line 4-4in FIGURE 2;

FIGURE 5 is a fragmentary cross-sectional view taken along the line 55in FIGURE 2;

FIGURE 6 is a fragmentary cross-sectional view taken along the line 66in FIGURE 2;

FIGURE 7 is a fragmentary cross-sectional view taken along the line 7-7in FIGURE 2;

FIGURE 8 is a further enlarged fragmentary crosssectional view takenalong the line 8-8 in FIGURE 2;

FIGURE 9 is a further enlarged fragmentary sectional in a cocked energystoring position;

Patented Jan. 23, 1968 v FIGURE is an enlarged and exploded perspectiveview of the internal portion of the actuator assembly showing thelocking and planetary cam release mechanism in accordance with thisinvention;

FIGURE 11 is a rearward perspective view of the spider portion of theplanetary cam release mechanism shown in FIGURE 10;

FIGURE 12 is an enlarged fragmentary sectional view of the actuator asshown in FIGURE 2 illustrated in fired or released position;

FIGURE 13 is a fragmentary cross-sectional view taken along the line13--13 in FIGURE 12;

FIGURE 14 is a further enlarged fragmentary sectional view taken alongthe line I4-14 in FIGURE 12;

FIGURE 15 is a further enlarged fragmentary crosssectional view takenalong the line 15-15 in FIGURE 12; and

FIGURE 16 is a further enlarged fragmentary sectional view of theactuator as shown in FIGURE 9, illustrated in the fired or releasedposition.

Referring generally to FIGURE 2, the actuator mecha- .nism in accordancewith this invention comprises a body or housing 10 which defines asubstantially cylindrical chamber 11. This housing 10 includes a supportbracket 12 having bolt holes 13 for securing the assembled actuator inthe proper position on a bomb release shackle (not shown). Housing 10 isfurther provided with a plug 14 and washer 15 which maintain theactuator components, described hereinafter, in proper assembled positionwithin the housing 10, and which seal one end of chamber 11 so that theassembly is not subjected to the moisture and dirt, or severetemperature variations of the surrounding atmosphere. The housing 10,plug 14 and washer 15 are preferably made from a metal having a highmagnetic reluctance.

This actuator mechanism also includes an electro-magnetic solenoid unit20 housed at one end of the chamber 11 and a spring-loaded plungerassembly 50 housed at the other end of the chamber. In accordance withthis invention, this solenoid unit 20 when energized operates throughnovel locking and release means 80 and planetary cam assembly 100 torelease this spring-loaded plunger assembly 50 and allow the plunger toforcefully impact a bomb shackle release lever.

Referring to FIGURE 2 more specifically, the solenoid unit 20 includes astator 21 having a central core portion 21' surrounded by the wireenergizing coil 23 that is wound about a coil spool 24. The left end ofthis stator core 21 in this embodiment, as viewed in FIGURE 2, extendsoutwardly beyond spool 24 and forms a tubular element 22 to receive theplunger assembly 50, as further described hereinafter, and the outer orperipheral portion of stator 21 provides four spaced pole pieces 27, 28,29 and 30 (FIGURE 3) which extend beyond spool 24 to the right in FIGURE2. The stator 21 is restrained from rotating within the housing 10 bythe Set screw 19, and the coil 23 can be connected to a suitable powersource (not shown) by lead wires that extend outwardly from the housingthrough a water-tight fitting 26.

This solenoid unit also includes a rotor 35 secured to a shaft 36. Thisrotor 35 defines four equally-spaced poles 37, 38, 39 and 40, as seen inFIGURES 3, 10 and 13, which are disposed adjacent the above-describedpole pieces 27, 28, 29 and respectively of the solenoid stator 21. Bythis arrangement, when the coil 23 of this solenoid 20 is energized,these poles on the rotor are attracted toward the respective adjacentpoles on the stator 21, as described in said above-mentioned patent, andimpart a counter-clockwise rotation to the shaft 36, as indicated by thearrow in FIGURE 3.

This rotor shaft 36, as shown in FIGURE 2, extends through stator 21 andtubular portion 22 along substantially the entire length of housingchamber 11, and is supported for rotation in the stator by sleevebearings 41 and 42. In addition, a stop-nut 43 and a thrust ball bearing44 operate to maintain the shaft 36 in the proper lateral positionwithin the actuator housing 10. This thrust hearing 44 also aids inmaterially reducing the amount of electrical energy needed to actuatethe mechanism in accordance with this invention by substantiallyreducing the drag on the rotor 35 created by the lateral pull of thesolenoid 20 on the rotor when the coil 23 is energized.

Referring to FIGURES 4 and 10 the rotor 35 is also provided with a stoppin 45 which extends inwardly from the rotor toward the stator 21 andwhich travels within an arcuate groove 46 provided in the adjacent faceof the coil spool 24. The upper limit of the groove 46 thereby providesan abutment shoulder 47 engageable with the pin 45 to define the extremeclockwise or cocked position of the rotor. A torsion spring 34, shownclearly in FIG- URES 3 and 13, is also included in the solenoid unit tourge the rotor 35 clockwise toward this cocked position, and to retainthe pin 45 in engagement with the shoulder 47 when the solenoid 20 isnot energized. FIGURES 4 and 13 further illustrate that this solenoidunit 20 includes a stop ring 48, formed from soft flux-permeable steelor the like, which is secured to the stator 21 by a suitable retainingclip 49. This stop ring 48 is provided with a tab 48 projecting into thepath of counter-clockwise travel of pin 45 on the rotor. The tab 48" isthus engageable with pin 45 to define the extreme counter-clockwiseuncocked or released position of the rotor 35, as illustrated in FIG-URE 13.

Since this arrangement in accordance with this invention places the stoptab 48' and the stop pin 45 in the magnetic circuit of the solenoid unit20, the energization of the coil 23 will magnetize the tab and pin, andcreate a mutual magnetic attraction which draws the pin toward the tab.In addition to providing a stop for the rotor 35, the tab 48' and pin 45therefore provide a supplementary magnetic torque force as the pinapproaches the tab which assists the rotation of rotor 35 through thefinal angular degrees where the torque force would otherwise be weakenedby the closing of the gaps between the rotor and stator poles of thesolenoid assembly.

To describe the bomb release-lever engaging portion of this actuator inmore detail, the plunger assembly 50 comprises a hollow cylindricalmember which is slidably extended over the tubular portion 22 of thestator core 21 and over the shaft 36 Within housing chamber 11. Astriking cap 56, which will engage the release-lever of the bomb shacklerelease device during operation of the actuator, is threaded to theouter end of member 55 (FIGURES 2 and 12) and a hollow cylindrical skirt57 is threaded to the periphery of member 55. The member 55, cap 56 andskirt 57 will thereby move longitudinally outward from within chamber 11as a complete unit, from the position shown in FIGURE 2 to the positionshown in FIGURE 12, when the actuator in accordance with this inventionis operated to release the bombs from the aircraft.

To limit the outward travel of this plunger assembly 50, the housing 10as shown in FIGURES 2 and 12 ineludes an inward circular flange 10'which surrounds the periphery of the skirt 57. A nylon channel-shapedliner 58, held in place against the skirt 57 by a suitable resilient Oring 59 is also provided within the housing 10, to insure that thesliding junction between skirt 57 and the flange 10 is sealed from theatmosphere surrounding the actuator. A split shock ring 60, havingbeveled edges 61 is positioned adjacent this 0 ring 59, and isengageable with an angular flange 63 on the skirt 57 to limit theoutward travel of plunger assembly 50. FIGURE 12 shows that theengagement between this flange 63 and the shock ring will force the ring60 outwardly to the left against the resilient O ring 59 whilesimultaneously forcing the ring 60 to radially expand into frictionalengagement with the housing 10. By this arrangement, the outward lateralmovement of the plunger assembly :50 is arrested in a manner whichcushions the impact between the skirt 57 and the housing so that shockand vibration forces resulting from the operation of the actuatormechanism are minimized.

As discussed in the aforementioned Patent 2,776,570, the energy storingmeans used in the type of actuators under consideration comprises astrong compression spring 70 which is substantially fully compressedwhen the actuator is locked in a cocked position, as illustrated inFIGURES 2 and 9, and which operates when unlocked to bring the plungerassembly 50 into engagement with the release-lever of the bomb shackledevice with a substantial impact force. In this embodiment, the energystoring compression spring 70, having a compressive force ofapproximately 30 pounds is mounted around the tubular portion 22 betweenthe stator 21 and the plunger assembly 50, and is operative upon releaseof the plunger assembly 50 to rapidly force the plunger outwardly untilthe motion is arrested by the engagement of flange 63 with the shockring 60, as described hereinabove. A key 75 secured to the tubularportion 22 of the stator 21 is in engagement with a longitudinal keyway76 provided in the interior surface of hollow member 55, and guides theoutward movement of plunger assembly 50 during the bomb-releasingoperation.

The bomb release actuator mechanism in accordance with this inventionfurther includes an improved locking and release latch 80, as seen inFIGURES 9 and 10, to releasably retain the plunger assembly 50 in acocked energy storing position. Latch 80 is pivotally mounted adjacentthe plunger assembly 50 on pins 81 within a longitudinal groove 79 inthe tubular portion 22 of the stator core. The latch 80 further includesa detent 82 which is engageable with an interior surface 83 of theplunger assembly 50. As shown in FIGURES 2 and 9, when this latch 80 ispivoted about pins 81 to a locked position, the detent surface 82engages with the interior surface 83. The plunger assembly 50 is therebyretained in a cocked position within the housing 10 and the energy ofthe compressed spring 70 is stored.

FIGURES l2 and 16 illustrate that this locking latch 80 in accordancewith this invention also pivots about the pins 81 into an unlockedposition to disengage the detent 82 from the interior surface 83 of theplunger assembly and thereby release the stored energy of the compressedspring 70. When the latch 80 is moved from the locked to the unlockedposition, it is apparent that spring 70 will then forceably drive theplunger assembly 50 outwardly against the release-lever of the bombshackle. To insure that the plunger assembly 50 is rapidly released, thelatch 80 in this illustrated embodiment is pivoted within the actuatorhousing 10 so that the compression spring 70 urges the latch toward thisunlocked position. As seen in FIGURE 9, the pivot pins 81 of the latchare thus secured to the actuator assembly in a position spaced from thedetent 82 so that a moment arm is defined between the pins and thedetent. The lateral releasing force of the compressed spring 70, appliedto the latch 80 through the detent 82, thereby creates a moment forcewhich tends to rotate the latch to the above-described unlockedposition. By this arrangement, the need for additional means to producea quick release of the latch 80 is eliminated.

The bomb release mechanism in accordance with this invention furtherincludes an improved planetary cam assembly 100 which is mounted onrotor shaft 36, and which cooperates with the latch 80 to releasablyretain the latch in a locked position against the biasing force ofspring 70. As illustrated in FIGURE 10, the planetary cam assembly 100comprises a cam sleeve 10'1 defining an arcuate cam surface 102 on itsperiphery, and a plurality of rolling cams 110, 111, 112 and 113.

When the cam means 100 is assembled on the rotor shaft 36, these rollingcams are uniformly spaced around the cam surface 102 and maintained inrolling contact therewith by being loosely held within slots 116 in aspider member 115. As shown in FIGURES 9 and 16, this 6 planetary camassembly in this embodiment is dimensioned for placement within araceway defined between the interior of tubular portion 22 and the camsurface 102 of the cam sleeve 101.

To control the movement of latch '80, this planetary cam means 100 ismounted on the shaft 36 'with the cam sleeve 101 spaced adjacent thelatch and positioned so that the planetary rolling cam is movablebetween the latch and cam sleeve along the cam surface 102 defined bythe sleeve (FIGURES 9 and 16). Axial movement of the cam assembly 100along shaft 36 is prevented by the adjustable nut 130 and washer 131 onthe left, as viewed in FIGURE 9, and by the cam nut on the right of thecam assembly. As shown in FIGURE 10, cam nut 120 is secured to shaft 36by a suitable set screw 121, and may be finally adjusted during theassembly of the actuator mechanism in accordance with this invention byinserting the proper adjustment tool through the apertures provided inthe tubular portion 22 of the stator. The positioning of the planetarycam means 100 by means of adjustable nut and the adjustable cam nut 120in accordance with this invention thereby allows final adjustment of therelative positioning of the locking latch 80 and cam means 100 at thetime of assembly, and eliminates the need for providing the bomb releasemechanism with expensive parts machined to close tolerances.

The mounting of cam means 100 on shaft 36 in the above-described mannerpermits the planetary rolling cam 110 to be moved into a position toeither lock or release the latch 80. In this first locking position ofrolling cam 110, as seen in FIGURE 7, the engagement of cam 110 betweenlatch 80 and cam sleeve 101 counteracts the above-described biasingforce of spring 70 which tends to rotate the latch to its unlockedposition, and releasably retains the latch locked against the plungerassembly 50. The underside of latch 80 preferably includes a recess 84which assists in retaining the rolling cam 110 in this first position.

FIGURE 15 further illustrates the movement of rolling cam 110 along thecam sleeve 101 to a second unlocked position removed from engagementbetween latch 80 and the cam sleeve. With rolling cam 1'10 in thissecond position, the biasing force of the compressed spring 70 willquickly force the latch 80 toward the unlocked position shown in FIGURE'16 and thereby release the plunger assembly 50. Latch 80 is preferablyprovided with a bevelled edge portion 85, shown in FIGURES 7 and 15,which engages rolling cam 110 and facilitates the movement of the cambetween the above-described first and second positions.

The movement of rolling cam 110 from the first position to the secondposition to release the latch 80 from the plunger 50 is selectivelycontrolled by the rotation of the rotor shaft 36 induced by theenergization of the solenoid 20. Projecting tongues 122 on cam nut 20operably engage with corresponding grooves 117 in the cam spider 115 andtransmit the rotation of shaft 36 to the rolling cams 110, 111, 112, and113, as seen in FIGURES 10 and 11.

FIGURE 6 illustrates the engagement of tongues 122 in the grooves 117with the bomb release actuator in a cocked energy storing position, andFIGURE 14 illustrates the position of tongues 122 within the groovesafter the actuator has been released or fired. FIGURES 6 and 14 furthershow that the arcuate width of the grooves 117 in the spider 115 issubstantially larger than the width of the corresponding tongues 122 sothat the rotation of shaft 36 causes the tongues 122 to pre-travelthrough a predetermined are before engaging with the spider 115 andactuating the release of the latch 80. This pre-travel feature of thisembodiment of the invention, in which the tongues 122 pre-travel throughapproximately fifteen degrees, provides a lost-motion connection betweenthe cam assembly 100 and the shaft 36 which permits the shaft to developa substantial amount of angular momentum before impacting the cam means100 and assures a positive and quick release of the plunger assembly 50,as further described hereinafter. The degree of angular rotation of thecam spider 115 and the limit of travel of the rolling cam 110 in thecocked position is controlled by the engagement of a stop pin 86,extending from the latch 80, within groove 118 (FIGURE 10) provided inthe periphery of the spider 115.

In operation, the bomb release actuator mechanism in accordance withthis invention is initially retained in a cocked energy storingposition, as illustrated in FIG- URES 2 and 9, with the plunger assembly50 releasa-bly locked by the latch 80. In this cocked energy storingposition, the solenoid is deenergized, and the force of torsion spring34 retains the rotor 35 in the position shown in FIGURE 3, with the stoppin 45 engaged against the shoulder 47. The pole pieces 37, 38, 39 and40 of the rotor 35 are thus initially maintained in a spaced or gappedposition with respect to the corresponding pole pieces 27, 28, 29 and 30of the stator 21. This securing of the rotor also prevents the rotationof rotor shaft 36 and cam nut 120.

During the assembly of the actuator, the cam nut 120 is adjusted toposition the spider 115 of cam means 100 so that the rolling cam 10 isretained in the locking position engaged with latch 80, as shown inFIGURE 7, when the rotor 35 is in the above-described starting position.The proper initial positioning of spider 115 brings the spider intoengagement with the pin 86 extending from the latch 80 into the spidergroove 118, as shown in FIG- URE 6. In addition, FIGURE 6 illustratesthat the cam nut 120 is adjusted on shaft 36 so that the tongues 122 onthe cam nut initially engage the spider 115 in an extreme clockwiseposition within grooves 117.

To release the plunger assembly 50 from this initial locked position, alow amperage energizing current is supplied to the coil 23 of solenoid20 through the lead wires 25. This energization of solenoid 20 rotatesthe shaft 36 and cam nut 120 counter-clockwise by attracting the rotorpoles 37, 38, 39 and 40 toward the stator poles 27, 28, 29 and 30respectively with a magnetic force sufficient to overcome the clockwisebiasing force of the torsion spring 34. After the rotor 35 and shaft 36have travelled through approximately 35 degrees in this embodiment ofthe invention, the rotation of the rotor and shaft is arrested byengagement between the stop pin and the tab 48, as illustrated in FIGURE13.

As explained hereinabove, the cam nut 120 will pretravel through an arcof approximately 15 degrees, and together with the rotor 35 will thusdevelop substantial angular momentum, before the tongues 122 on the camnut impact against the counter-clockwise edge of the grooves 117 (FIGURE14) and transfer the rotation of shaft 36 to the cam spider 115. Thecontinued rotation of shaft 36 will then cause the spider 115 to forcethe rolling cam 110 from the locked position as shown in FIGURE 7 to asecond or unlocked position, illustrated in FIGURE 15. The force ofcompressed spring 70, which urges the latch 80 downward as viewed inFIG- URE 15, will assist in moving rolling cam 110 to this secondposition by the engagement of the cam with the bevelled surface 85, andWill then quickly move the latch downward to its unlocked positiondisengaged from the plunger assembly 50. It is apparent from the abovedescription that the movement of latch 80 to the unlocked positionthereby releases the plunger assembly 50 from a cocked position, andpermits the plunger to be driven outwardly from housing 10 into impactwith a bomb shackle release-lever by the expansion of the compressionspring 70. It is further apparent from the above descrip tion that theactuator in accordance with this invention requires less electricalenergy to release, since the rolling contact between the rolling cam 110and the latch 80 minimizes the frictional resistance of the assembly.

To recoc-k the actuator for further use, the plunger assembly 50 isforced inwardly, by any suitable means, until the spring 70 iscompressed and the interior surface 83 on the plunger clears the detent82 on the latch 8i The torsion spring 34, shown in FIGURE 13, will thenrotate the shaft 36 and the interconnected rolling cam 11% clockwise,and cause the rolling cam to force the latch 85 up into the lockedposition against the plunger assembly. The actuator assembly inaccordance with this invention is thus placed in an energy-storingcondition, and may be released by selectively repeating the energizationof the coil 20.

It will be appreciated that the foregoing description is merelyillustrative of one embodiment of the energy storing and releasemechanism in accordance with this invention. Various modifications ofthe aforementioned embodiment may be devised by those skilled in the artwithout departing from the scope of this invention, as set forth in theaccompanying claims.

What is claimed is:

1. An energy storing and release mechanism comprising:

a housing defining an elongated chamber,

a plunger mounted within said chamber and longitudinally movable thereinfrom an energy storing cocked position to a released position,

energy storing means retained within said housing and operable to movesaid plunger from said cocked position to said released position,

locking means supported within said housing adjacent said plunger, saidlocking means having a locked position in engagement with said plungerto releasably retain said plunger in said cocked position and furtherhaving an unlocked position disengaged from said plunger permitting saidenergy-storing means to move said plunger toward said released position,

a shaft rotatably mounted within said chamber adjacent said plunger,

planetary cam means positioned on said shaft and operable to releasablyretain said locking means in said locked position, said cam meanscomprising a cam sleeve mounted on said shaft and defining an arcuatecam surface spaced adjacent said locking means and further comprising aplanetary rolling cam engaged with said cam surface and movable thereonto a first position engageable between said cam surface and said lockingmeans to releasably retain said locking means in said locked position,said planetary rolling cam being further movable on said cam surface toa second position permitting said locking means to move to said unlockedposition,

means to selectively rotate said shaft, and

connecting means joining said planetary cam means to said shaft andoperable to move said planetary rolling earn from said first position tosaid second position in response to rotation of said shaft and therebypermit said locking means to move to said unlocked position and releasesaid plunger.

2. An energy storing and release mechanism according to claim 1 whereinsaid connecting means between said shaft and said planetary cam meanscomprises a lost-motion connection permitting said shaft to pretravelbefore transmitting rotation to said cam means, whereby said connectingmeans quickly moves said rolling cam from said first position to saidsecond position with substantial angular momentum.

3. An energy storing and release mechanism according to claim 1 where-insaid means to selectively rotate said shaft comprises a solenoidsupported in said housing adjacent said shaft and wherein said solenoidincludes a rotor joined to said shaft and operative to rotate said shaftu-pon energization of said solenoid.

4. An energy storing and release mechanism comprising:

a housing defining an elongated chamber,

a hollow plunger mounted within said chamber and longitudinally movabletherein from an energy storing cocked position to a released position,

energy storing biasing means retained within said housing and operableto forcefully move said plunger from said cocked position to saidreleased position,

locking means movably supported adjacent the interior of said hollowplunger, said locking means having a locked position in engagement withan interior surface on said plunger to releasably retain said plunger insaid cocked position and further having an unlocked position disengagedfrom said plunger permitting said biasing means to move said plungertoward said released position,

a shaft rotatably mounted in said chamber and extending Within saidhollow plunger,

planetary cam means positioned on said shaft within said hollow plungerand operable to releasably retain said locking means in said lockedposition, said cam means comprising a cam sleeve mounted on said shaftand defining an arcuate cam surface spaced adjacent said locking meansand further comprising a planetary rolling cam engageable with said camsurface and movable thereon to a first position engaged between said camsurface and said locking means to releasably retain said locking meansin said locked position engaged with said plunger, said planetaryrolling cam being further movable on said cam surface to a secondposition permitting said locking means to move to said unlockedposition,

means to selectively rotate said shaft within said hollow plunger, and

connecting means joining said planetary cam means to said shaft andoperable to move said rolling cam from said first position to saidsecond position in response to rotation of said shaft and thereby permitsaid locking means to move to said unlocked position and release saidplunger.

5. An energy-storing and release mechanism according to claim 4 whereinsaid connecting means comprises a cam nut fixed to said shaft and a camspider movably mounted about said shaft in engagement with said rollingcam and wherein said cam nut and spider are connected by a tongue andgroove connection so that said spider transmits the rotation of said camnut to said rolling cam.

6. The invention according to claim 5 wherein said groove in said tongueand groove connection between said spider and cam nut is substantiallylarger than said tongue so that said shaft pre-travels and developssubstantial angular momentum before transmitting rotation to saidrolling cam.

7. An energy storing and release mechanism in accordance with claim 4wherein said locking means comprises a latch pivotally mounted withinsaid chamber and extending within said hollow plunger, said latchincluding a detent engageable with said plunger to releasably retainsaid plunger in said cocked position and further in cluding a surfaceengageable with said rolling cam so that said rolling cam movablyretains said detent of said latch in engagement with said plunger.

8. An energy storing and release mechanism according to claim 4 whereinsaid means to selectively rotate said shaft comprises a solenoidsupported in said housing about said shaft and wherein said solenoidincludes a rotor joined to said shaft and operative to rotate said shaftthrough a predetermined angle upon energization of said solenoid.

9. An energy storing and release mechanism compris- 1n a housingdefining an elongated chamber,

a plunger mounted within said chamber and longitudinally movable thereinfrom an energy storing cocked position to a released position,

energy storing means retained within said housing and operable to movesaid plunger from said cocked position to said released position,

locking means supported within said housing adjacent said plunger, saidlocking means having a locked position in engagement with said plungerto releasably retain said plunger in said cocked position and furtherhaving an unlocked position disengaged from said plunger permitting saidenergy-storing means to move said plunger toward said released position,

cam means cooperating with said locking means comprising a cam surfacespaced adjacent said locking means and a rolling cam movable on said camsurface into a first position engaged between said cam surface and saidlocking means to releasably retain said locking means in said lockedposition, said rolling cam further movable on said cam surface to asecond position permitting said locking means to move to said unlockedposition, and

a solenoid supported in said housing adjacent said plunger including arotor joined to said cam means, said rotor being operative uponenergization of said solenoid to move said rolling cam from said firstposition toward said second position over said cam surface so that saidcam means unlocks said locking means and permits said energy-storingmeans to forceably drive said plunger to said released position.

10. An energy-storing and release mechanism comprising:

a housing defining an elongated chamber,

a plunger mounted with-in said chamber and longitudinally movabletherein from an energy storing cocked position to a released position,

energy-storing means retained within said housing and operable to movesaid plunger from said cocked position to said released position,

locking means supported within said housing adjacent said plunger, saidlocking means having a locked position in engagement with said plungerto releasably retain said plunger in said cocked position and furtherhaving an unlocked position disengaged from said plunger permitting saidenergy-storing means to move said plunger toward said released position,

a shaft rotatably mounted within said chamber adjacent said plunger,

planetary cam means joined to said shaft and operably movable to a firstposition engaged with said locking means to releasably retain saidlocking means in said locked position, said planetary cam means beingfurther movable to a second position permitting said locking means tomove to said unlocked position,

means to selectively rotate said shaft, and

connecting means joining said planetary cam means to said shaft andoperable to move said cam means from said first position to said secondposition in response to rotation of said shaft and thereby permit saidlocking means to move to said unlocked position and release saidplunger.

11. An energy-storing and release mechanism in accordance with claim 10wherein said locking means includes a recess engageable with said cammeans to resist movement of said cam means from said first position, andwherein said locking means further includes a bevel adjacent said recessto urge said cam means toward said second position as said cam meansdisengages from said recess.

12. An energy-storing and release mechanism according to claim 10wherein said connecting means between said shaft and said planetary cammeans comprises a lostmotion connection permitting said shaft topre-travel before transmitting rotation to said cam means, whereby saidconnecting means quickly moves said cam means from said first positionto said second position with substantial angular momentum.

13. An energy-storing and release mechanism in accordance with claim 10wherein said locking means is pivotally supported at a position spacedfrom the point of engagement between said locking means and said 1 1 1 2plunger so that said energy-storing means urging said References Citedplunger toward said rel eased nosmon operates through 3. UNITED STATESPATENTS lever-arm defined by said locking means to forcea-bly urge saidlocking means toward said unlocked position, where- 1,510,445 9/ 1924 Hy by said energy-storing means is operative to quickly move 5 2,535,09512/1950 war z et al- 74-2 said locking means to said unlocked positionin response to movement of said cam to said second position. MILTONKAUFMAN, 'y Examiner-

